In a system employing shared channels, a portion of the shared resource is allocated to user equipment (UEs) on a round-by-round basis. The amount of the shared resource allocated to a user is measured in the smallest individual unit of the shared resource that can be allocated; this is called a resource unit.
Depending on the prevailing radio channel conditions the number of information bits that can be transferred in each resource unit will vary. It is likely that in a cellular system the number of bits transferred per resource unit will vary greatly across the coverage area of the cell.
In this environment it is desirable to provide the same overall throughput to packet users regardless of the radio conditions they experience.
Conventionally either:
    The number resource units allocated per round of allocation is fixed, regardless of the number of information bits that can be transferred in each resource unit. or    Resource units are allocated so that an equal volume of data is transferred to each user in each round of allocation.Allocating a fixed number of resource units per round of allocation to all users has the disadvantage that some users will experience very much poorer throughputs than others. However, this method has the advantage that overall throughput in the cell will be maximised.
Allocating the appropriate number of resources so that a fixed volume of data is transferred has the disadvantage that overall cell throughput is reduced. However, this method has the advantage of providing even throughput to all users irrespective of their channel conditions.
The optimum condition required by the operator of the system may lie somewhere between these two extremes.
A need therefore exists for control of resources amongst users with different instantaneous throughputs wherein the abovementioned disadvantage(s) may be alleviated.